In a friction welding process, such as a conventional spin welding process, the components to be welded are placed in close proximity to each other and rotated at high relative rates of speed in conjunction with an applied axial clamping force. Heat generated at or along an interface between the components melts a portion of the component material. The molten material that flows away from the interface or the weld zone is referred to as molten flash. When the molten flash cools, a homogenous welded joint is formed in the weld zone from the intermixed component materials.
Spin welding provides many advantages, e.g., relatively short cycle times, large batch sizes, and high overall process efficiency. Spin welding also provides excellent repeatability when used in conjunction with precise process control methods, such as controlled material feed and/or spin rates, axial pressures, applied stroke, etc. However, the bonding strength and long term durability of a welded joint formed via a conventional spin welding process may be less than optimal when used in certain applications, and therefore spin welding is generally restricted to welding relatively small cylindrical parts of similar materials, largely in order to maximize the strength of the resultant welded joint.